Drilling apparatus having drill steel rotation control



Oct. 8, 1968 M. WORMAN 3,404,739

DRILLING APPARATUSv HAVING DRILL STEEL ROTATION CONTROL Filed March 11, 1966 INVENTOR. MA R7 IN WORMA/V United States Patent DRILLING ABSTRACT OF THE DISCLOSURE A drilling apparatus including a percussively and rotatably driven drill steel. The drilling apparatus is provided with means for interrupting the driven rotation of the drill steel and means for holding the drill steel to prevent free rotation thereof, such means both being actuated by a single control means.

This invention relates to drilling apparatus and has more particular reference to the provision of a new and improved drilling apparatus wherein means are provided for controlling the rotation of the drill steel.

conventionally, drilling apparatus has sometimes been provided with a mechanism for interrupting the driven rotation of the drill steel such that the drilling apparatus may be employed without a rotatably driven drill steel. The mechanisms of this type heretofore employed, however, have permitted free rotation of the drill steel in the intervals during which the drill steel was not rotatably driven. Thus, although these prior mechanisms did prevent the drill steel from being rotatably driven by the drilling apparatus, they did not lock the drill steel against free rotation.

The employment of a drilling apparatus as a paving breaker necessitates that all rotation of the drill steel, including free rotation thereof, be eliminated. Hence, drilling apparatus including these prior mechanisms is generally unsuitable for application as a paving breaker in view of the free rotation permitted the drill steel by these prior mechanisms.

An object of the present invention is to provide a new and improved drilling apparatus wherein means are provided for locking the drill steel against rotation such that the drilling apparatus may be employed as a paving breaker or the like.

Another object of the invention is to provide a new and improved drilling apparatus wherein means are provided for interrupting the driven rotation of the drill steel without interrupting the operation of the motor of the drilling apparatus.

Another object is to provide a new and improved drilling apparatus including means of the type set forth which are relatively simple and economical in construction and highly dependable and eflicient in operation.

These objects, and the other objects and advantages of the invention which will be apparent from the following description taken in connection with the accompanying drawings, are obtained by the provision of a new and improved drilling apparatus comprising a housing and a drill steel associated with the housing. A reciprocating piston is disposed within the housing for percussively driving the drill steel; and a means is provided for rotating the drill steel. The drilling apparatus also includes means actuatable for interrupting the rotation of the drill steel by the drill steel rotating mean-s, means actuatable for holding the drill steel against free rotation thereof, and single control means for actuating both the drill steel rotation interrupting means and the drill steel holding means.

Referring to the drawings:

FIG. 1 is a longitudinal view, partially broken away and in section, of a drilling apparatus constructed in accordance with the present invention;

FIG. 2 is a sectional view of the drilling apparatus shown in FIG. 1 taken on line 22 of FIG. 1, looking in the direction of the arrows;

FIG. 3 is an enlarged, sectional view of the drilling apparatus shown in FIG. 1 taken on line 33 of FIG. 1, looking in the direction of the arrows; and

FIG. 4 is an exploded view illustrating the locking means for preventing the rotation of the drill steel of the drilling apparatus shown in FIG. 1.

Referring more particularly to the drawings wherein similar reference characters designate corresponding parts throughout the several views, FIG. 1 illustrates a drilling apparatus designated generally as 10 which includes an elongated housing 12 having an axial bore 14. A drill steel 16 of hexagon cross section is disposed with a shank portion 16a extending into the bore 14 at the forward end 12a of the housing 12 and projects longitudinally forward of the forward end 12a of the housing 12.

A reciprocating piston 18 is disposed within the bore 14 rearwardly of the shank portion 16a of the drill steel 16. The piston 18 is longitudinally slideable in the bore 14 to deliver impact blows to the shank portion 16a of the drill steel 16 to percussively drive the latter. The Sliding movement of the piston 18 in the bore 14 is controlled by a conventional flapper valve (not shown) which is carried by the rearward end 12b of the housing 12. The housing 12 is provided with an inlet air connection 20 which, during the operation of the drilling apparatus 10, is suitably connected to a source (not shown) of pressurized air to introduce pressurized air into the housing 12 for actuating the piston 18. The housing 12 is also provided with an exhaust air connection (not shown) which communicates with the bore 14 through a plurality of exhaust passages 22 for discharging exhaust air from the bore 14 to atmosphere. The admission of pressurized air through the inlet air connection 20 is manually controllable by an operating lever 24 which is disposed at the rearward end 12b of the housing 12 adjacent the drill carrying handle 26.

The drill steel 16 and the piston 18 include aligned, axial passages (not shown) which extend longitudinally therethrough. A water supply tube 28 is disposed with one of its longitudinal ends extending into the axial passage in the piston 18. The opposing longitudinal end of the water supply tube 28 is connected to an inlet water connection 30 disposed at the rearward end 12b of the housing 12. The inlet water connection 30, during the operation of the drilling apparatus 10, is connected to a source (not shown) of water for directing water through the water supply tube 28 and the axial bores in the drill steel 16 and the piston 18 to the drilling surface (not shown).

The piston 18 is provided with a plurality of straight splines 32 which are formed longitudinally on the piston 18 adjacent the forward end thereof. A chuck driver or driving sleeve 34 is disposed within the housing 12 circum ferentially around the forward end of the piston 18 and is sufficiently spaced from the latter to permit longitudinal movement of the piston 18 relative to the chuck driver 34. The chuck driver 34 is provided with a plurality of straight splines 36 which engage with the straight splines 32 formed on the piston 18 to provide conjoined rotation of the piston 18 and the chuck driver 34 upon rotation of the piston 18.

The forward end of the chuck driver 34 is formed with a plurality of driving jaws 38. A chuck 40 is disposed within the housing 12 forward of the chuck driver 34 and is axially aligned with the chuck driver 34. The rearward end of the chuck 40 is formed with a plurality of driven jaws 42 which engage with the driving jaws 38 on the chuck driver 34 such that rotation imparted to the chuck driver 34 by the piston 18 is transmitted to the chuck 40. The chuck 40 includes an axial bore 44 of hexagon cross section which tightly receives the shank portion 16a of the drill steel 16 such that the rotation received by the chuck 40 is delivered to the drill steel 16.

The piston 18 is provided with a plurality of spiral splines 46 which are formed longitudinally on the piston 18 and extend adjacent the forward end thereof. A ratchet ring 48 is disposed within the housing 12 adjacent the rearward end of the chuck driver 34 and extends circumferentially around the piston 18. The ratchet ring 48 receives the piston 18 to permit longitudinal movement of the piston 18 relative to the ratchet ring 48. The internal circumference of the ratchet ring 48 includes a plurality of spiral splines 50 which are in engagement with the spiral splines 46 formed on the piston 18.

The external circumference of the ratchet ring 48 is formed with a plurality of ratchet teeth 52. A pair of pawl elements 54 are pivotably mounted upon the housing 12 adjacent the external circumference of the ratchet ring 48 for movement between positions in engagement with the ratchet teeth 52 and positions spaced radially outward therefrom. The pawl elements 54 are each biased towards the ratchet teeth 52 by a spring element 56 such that the pawl elements 54 normally engage the ratchet teeth 52. In this engaging position, the pawl elements 54 restrain the ratchet ring 48 from rotation to thereby cause rotation of the piston 18. In their positions spaced from the ratchet teeth 52, the pawl elements 54 permit rotation of the ratchet ring 48 and, thereby, interrupt the rotation of the piston 18.

A means is provided for retaining the pawl elements 54 in their positions spaced from the ratchet teeth 52 to cause this interruption of the rotation of the piston 18. This means comprises an annular sleeve 58 which is disposed intermediate the ratchet teeth 52 and the pawl elements 54. The sleeve 58 includes a pair of slots 60 which are positioned to permit simultaneous engagement of the pawl elements 54 with the ratchet teeth 52. The sleeve 58 is rotatable relative to the ratchet ring 48 and the pawl elements 54 between a position wherein the slots 60 are in alignment with the pawl elements 54 and a position wherein the slots 60 are moved out of alignment with the pawl elements 54. The sleeve 58 retains the pawl elements 54 in positions spaced radially outward from the ratchet teeth 52 when in the latter position and, thus, causes an interruption in the rotation of the piston 18.

The sleeve 58 includes a depending tang or finger portion 62 which extends adjacent the rearward end of the chuck driver 34. The housing 12 includes an opening 64 which extends transversely therethrough adjacent the rearward end of the chuck driver 34. The opening 64 receives the tang 62 and communicates with the bore 14 formed longitudinally in the housing 12 such that the chuck driver 34 forms one wall of the opening 64. A locking rod or control means 66 is slideably disposed through the opening 64 with one of its longitudinal ends projecting from the opening 64 and the other thereof extending to the end of the opening 64 on the opposite side of the housing 12.

The locking rod 66 is formed with a slot 68 which is dimensioned to tightly receive the forward end of the tang 62. The slot 68 keys the tang 62 to the locking rod 66 such that longitudinal movement of the locking rod 66 provides rotary movement of the sleeve 58. The locking rod 66 also includes a flat 70 which is formed on the face of the locking rod 66 adjacent the chuck driver 34. The chuck driver 34 is provided with a corresponding flat 72 on its outer circumference which is adapted to be engaged by the flat 70 on the locking rod 66 to key the chuck driver 34 to the locking rod 66 whereby the flats 70, 72 cooperate as a means for holding the drill steel 16 against free rotation. The slot 68 in the locking rod 66 is formed intermediate the ends of the flat '70 thereon such that longitudinal movement of the locking rod 66 provides substantially simultaneous rotation of the sleeve 58 and locking of the chuck driver 34.

A retaining mechanism is provided for limiting the longitudinal movement of the locking r'od'66 to'retain the locking rod I 66 within the opening 64. The retaining mechanism compriss 'a slot 74 which is formedinj the locking rod 66 in overlapping relationship withthe flat 70 on the actuating rod 66. Eachof the longitudinal ends of the slot 74 is formed with a tapered detent 76. A retaining member 78 having a sirriilarly tapered engagement finger 80 extending into the slot 74 is biased with the engagement finger 80 in contact with the locking rod 66 by a spring 82 which is located between the retaining member 78 and a screw cap 84 threaded to the housing 12. The tapered detents 76 and the retaining member 78 are relatively positioned such that the engagement of the tapered detent 76 formed at the longitudinal end of the slot 74 overlapping the flat 70 by the engagement member 78 looks the locking rod 66 in a position wherein the pawl elements 54 are in engagement with the ratchet teeth 52 and the chuck driver 34 is freely rotatable. Similarly, the engagement of the tapered detent 76 at the opposing end of the slot 74 by the engagement member 78 locks the locking rod 66 in a position wherein the sleeve 58 holds the pawl elements 54 in spaced relationship to the ratchet teeth 52 and the flats 70 and 72 are in locking engagement.

The operation of the before-described drilling apparatus 10 is believed to be apparent from the foregoing description. However, for the purposes of clarity and completeness of description, a brief summary of the operation of the drilling apparatus 10 will now be described.

With the locking rod 66 positioned to align the openings 60 in the sleeve 58 with the pawl elements 54 and the flats 70 and 72 held out of locking engagement, the drilling apparatus 10 is fully operable as a rock drill. More specifically, as the piston 18 slides longitudinally in the housing 12 under the influence of the pressurized air entering through the inlet air connection 20 and exhausting through the exhaust air connection (not shown), the pawl elements 54 engage the ratchet teeth 52 to restrain rotation of the ratchet ring 48. Thus, the piston 18 is caused to rotate during its slideable movement. This rotation of the piston 18 is transmitted to the drill steel 16 through the chuck driver 34 and the chuck such that the drilling apparatus 10 is provided with a rotating drill steel 16.

To operate the drilling apparatus 10 as a paving breaker, the locking rod 66 is longitudinally displaced to the posi tion shown in FIG. 3. This movement of the locking rod 66 rotates the sleeve 58 to move the openings therein out of alignment with the pawl elements 54. Thus, the sleeve 58 pivots the pawl elements 54 from engagement with the ratchet teeth 52 and retains such in spaced relationship as shown in FIG. 2. This movement of the locking rod 66, also, simultaneously locates the flat on the locking rod 66 in engagement with the flat 72 on the chuck driver 34. Should the chuck driver 34 be rotated to position the fiat 72 on a side thereof remote from the flat 70 on the locking rod 66, the engagement of the flats 70 and 72 will be delayed until the chuck driver 34 is rotated to locate the flat 72 in engagement with the fiat 70. The engagement of the flats 70 and 72 keys the chuck driver '34 to the locking rod 66 to prevent rotation of the chuck driver 34. Thus, the chuck 40 and the drill steel 16 held thereby are prevented from free rotation while the pawl elements 54 are out of engagement with the ratchet teeth 52. h 7

Therefore, as the piston 18 longitudinally slides within the housing 12, the ratchet ring 48 rotates and the piston 18 is maintained rotatably immobile. The drilling apparatus 10 then includes a nonrotatable drill steel 16 and is suitable for employment as a paving breaker or the like wherein a nonrotatable drill steel is required.

From the foregoing, it will be seen that the drilling apparatus may readily and simply be adapted for use as either a rock drill with a rotating drill steel 16 or as a paving breaker with a locked drill steel 16 by the mere adjustment of the locking rod 66. From the foregoing, it will be seen that I have provided new and improved means for accomplishing all of the objects and advantages of my invention.

However, although I have illustrated and described only a single embodiment of my invention, it will be understood that my invention is not limited merely to this illustrated and described embodiment, but rather encompasses other embodiments and variations employing the concepts and teachings of the hereindisclosed embodiment of my invention.

Having thus described my invention, I claim:

1. A drilling apparatus comprising a housing, a drill steel having an end extending into said housing and projecting longitudinally from the latter, a reciprocating piston disposed in said housing for percussively driving said drill steel, means for rotating said drill steel, means actuatable for interrupting the rotation of said drill steel by said drill steel rotating means, means actuatable for holding said drill steel against free rotation, and single control means for actuating both said drill steel rotation interrupting means and said drill steel holding means.

2. A drilling apparatus according to claim 1, wherein said drill steel rotating means comprises means for rotating said piston and means for transmitting the rotation of said piston into rotation of said drill steel, and said drill steel rotation interrupting means is operatively connected to said piston to interrupt the rotation of said piston.

3. A drilling apparatus according to claim 1, wherein retaining means are provided for locking said control means in a plurality of alternative positions, said posi tions including one in which said control means actuates both said drill steel rotation interrupting means and drill steel holding means and one in which both of said latter means are unactuated.

4. A drilling apparatus according to claim 1, wherein said control means comprises a rod axially movable to provide said actuation of both said drill steel rotation interrupting means and said drill steel holding means.

5. A drilling apparatus according to claim 1, wherein said drill steel rotating means comprises a ratchet ring, a pawl element interengageable with said ratchet ring for causing rotation of said piston, and means for transmitting rotation of said piston into rotation of said drill steel; said drill steel rotation interrupting means comprises a rotatable sleeve intermediate said ratchet ring and pawl element for retaining said pawl element out of engagement with said ratchet ring and having an opening for permitting engagement of said ratchet ring by said pawl element; said control means comprises an axially movable rod keyed to said sleeve whereby its axial movement causes rotation of said sleeve; and said drill steel holding means comprises interengageable locking surfaces on said rod and said rotation transmitting means.

6. A drilling apparatus according to claim 5, wherein said rotation transmitting means comprises a first sleeve element keyed to said drill steel for rotation therewith, and a second sleeve element arranged to be rotatably driven by said piston and including said locking surface on said rotation transmitting means, said sleeve elements being interconnected whereby rotation of said second sleeve element provides conjoined rotation of said first sleeve element.

7. A drilling apparatus according to claim 5, wherein retaining means are provided for locking said control means in a plurality of alternative positions, said positions including one in which said control means actuates both said drill steel rotation interrupting means and drill steel holding means and one in which both of said latter means are unactuated.

References Cited UNITED STATES PATENTS 1,962,684 6/ 1934 Gartin l7396 2,910,046 10/1959 Lear 173-111 X 3,143,931 8/1964 Worman 173--96 X 3,171,501 3/1965 Lear l7396 FOREIGN PATENTS 1,117,068 11/1961 Germany.

879,530 10/ 1961 Great Britain.

DAVID H. BROWN, Primary Examiner. 

